Endoscope-Assisted Contralateral Perimedian Supracerebellar Suprapineal Approach to Third Ventricle Surface of the Thalamus: 3-Dimensional Operative Video.

In managing thalamic gliomas, total surgical removal is the most effective way of increasing overall survival. However, the thalamus is a difficult target because of surrounding neurovascular structures. According to the lesion's size/location/growth pattern, relation to neighboring structures, and surgeon's experience, most thalamic lesions can be reached through one of the 4 free surfaces: lateral ventricle, velar, cisternal, and third ventricle surfaces of the thalamus (3VsT).1-3 Approaching the thalamic lesions through the lateral side disrupts the integrity of internal capsule and corona radiata; thus, we never prefer this approach. For the removal of the lesions on the 3VsT, a transcallosal approach can be considered, but with this approach, we cannot reach 3VsT without harming the velar surface.  In this 3-dimensional video, we demonstrate an endoscope-assisted contralateral perimedian supracerebellar suprapineal (CPeSS) approach to a glioma on the 3VsT. The patient, a 49-yr-old man, had progressive dizziness for a month. With the patient in a semisitting position, total resection was achieved via the endoscope-assisted CPeSS approach. This approach is entirely transcisternal-transventricular and is a natural route to the 3VsT. Although the route is longer than the ipsilateral approach, it requires no retraction and provides more direct and wider visualization. It allows complete visualization of the lateral border of the lesion. A perimedian approach also avoids the major tentorial bridging veins, which are mostly at the midline. High-definition neuroendoscope was a great adjunct that helped to visualize residual tumors at hidden corners.  We suggest this approach for thalamic lesions on the third ventricle surface of the thalamus.  The patient consented to the publication of his images and a written consent was obtained.